Cell Bio Flashcards
Which of the following DOES NOT inhibit microtubular polymerization?
Taxol
The structure of bio membranes best described
A fluid-mosaic of proteins interspersed in a phospholipid bilayer
Simple, non-ciliated columnar epithelium is most likely found associated with?
Digestive tract
Which of the following statements correctly describe the nucleolus?
It is the site for synthesis of rRNA
During the cell cycle, there are several checkpoints to ensure everything is ready prior to. One is the microtubule check point; this specific occurs during which stage?
M
Nuclear lamins are intermediate filaments that:
Line the inner aspect of the nuclear envelope
A connexon is a structural component of the
Gap Junctions
T/F Each microtubule consists of thirteen protofilaments?
True
Which of the following junctional complexes provide a tight seal between adjacent epithelial cells and serves as a barrier for paracellular transport?
Zonula occludens
Junctional complexes are associated with which cellular domain?
Basolateral
Which of the following group of cell adhesion molecules is calcium independent and mainly involved in cell-extracellular matrix and to the internal cytoskeleton?
Integrins
Which of the following categories of membrane proteins are represented by proteins that have a hydrophobic domain and two hydrophilic domains?
Transmembrane proteins
SNARE, SNAP and VAMP are associated with which of the following processes?
Vesicle and target membrane docking
Which of the following groups of CAMs functions through carbohydrate binding?
Selectins
T/F Some cargos are stored in secretory vesicles within the cytoplasm and released in response to a specific extracellular signal such as a hormone. This is referred to as constitutive.
False
Transport complexes that serve to transport proteins across outer mitochondrial membrane in the intermembrane space, from which they may be further transported across the inner membrane and perhaps into the matrix are referred to as
TOMs
Synthesis of materials required for mitosis occurs during which stage of cell cycle?
G2
Transitional epithelium associated with
Urinary
During which part of the cell cycle to chromosomes consists of two chromatids each?
Late G2
Which of the following promotes the formation of stable complexes between exportins and their cargo protiens?
Ran-GTP
Linker DNA is associated with which histone
H1
In the cytoplasm, as part of the process for moving materials across the nuclear membrane of the following converts Ran-GTP to Ran-GDP
Ran-GAP
Which of the following motor molecules consists of one head domain binding to actin and one tail domain binding to the cell membrane of a cargo vesicle?
Myosin I
Which of the following statements is TRUE
Coatemers are removed shortly before docking with their target membranes
Which of the following is located within the membrane of phospholipid bilayer and moderates membrane fluidity by restricting movement
Cholesterol
Which of the following forms caps and prevents elongation of actin filatments
Cytochalasin
Which of the following is not a type of intermediate filament
Fibronectin
Which type of membrane transport molecule carries 2 molecules simultaneously in opposite directions
Antiporter
Freeze-fracture of membranes has provided information on the intramembranous distribution of
Proteins
A cell junction that joins one epithelial cell to ALL its immediately neighboring cells is a
Tight junction
T/F All rRNA molecules are transcribed using RNA polymerase I
True
Ends of chromosomes which shorten with each cell cycle and are thought to limit the number of cell divisions
Telomeres
Prior to mitosis, concentrations of S cyclins occurs during which of the following stages?
G1
Which of the following is not a type III intermediate filament?
Nuclear lamins
At which stage of mitosis are the chromosomes lined up on the equatorial plate
Metaphase
At which stage of mitosis do sister chromatids move to opposite poles
Anaphase
N-CAMs, ICAMs and CD4 belong to which of the following group of CAMs?
Immunoglobulin superfamily molecules
Which of the following actin-linking proteins bundle actin filaments together in microvilli?
Villin and fimbrin
Coatamers cover which of the following types of vesicles
Vesicles being transported from the RER to the cis-Golgi face
Endothelium is associated with
Cardiovascular system
Which of the following is correct:
i. p53 is activated by dna damage
ii. when phosphorylated, the Rb gene product permits cell proliferation.
Both statements are correct
Which of the following is NOT one of the three properties of stem cells
Postmitotic
Which of the following phospholipids is found ONLY in the inner leaflet of the plasma membrane?
Phosphatidyinositol
Which of the following type of epithelium is found in the striated ducts of compound glands?
Cuboidal transitioning to columnar
Which of the following organelles is characterized by the presence of catalase?
Peroxisome
Simple vs compound glands are best described by this characteristic
Absence vs presence of ductal branching
Glands characterized by sebaceous in which the entire secretory cell is lost as part of secretion is
Holocrine
Which of the following organelle is characterized by hydrogen pump
Secondary lysosomes
Which of the following components would not normally be found in mitochondrial matrix>
Cytochromes
Secondary lysosomes may be associated with:
All of the above
- phagosomes
- late endosomes
- autophagosomes
The G protein consists of several subunits. Which of the following subunits exhanges its GDP for GTP when activated?
Alpha subunit
Which of the following signal molecules does not bind to an intracellular receptor?
Acetylcholine
Caspases are generally divided into two groups: initiators and executioners. Which of following apoptotic pathway utilizes caspase-8 as an initiator?
Fas pathway
Which of the following events is NOT characteristic of apoptosis?
Activation of inflammatory processes
The transport of proteins into the mitochondrial matrix is assisted by which of the following;
Hsp 60 and Hsp 70
Which of the following helps to create impermeability to small molecules across the membranes of the mitochondrial cristae?
Cardiolipin
In the ERK-MAP kinase pathway, activation of the GTP-binding protein Ras interacts with Raf kinase. Raf phosphorylates and activates which of the following?
MEK
In the JAK-STAT pathway, a ligand binds to a membrane receptor. Associated with this receptor is molecule “A”. Molecule “B” binds to A, resulting in the phosphorylation and dimerization of molecule B. What is identification of B?
STAT
This molecule attaches itself to a target protein and marks it for degradation by the 26S proteasome?
Ubiquitin
In the cyclic AMP second messenger pathway which of the following degrades the cAMP?
Phosphodiesterase
Which of the following ions is usually necessary to promote cell-to-cell adhesion in tissue cultures?
Calcium
T/F In neurons, cytoplasmic dyneins transport vesicles toward the nerve cell body
TRUE
Highly keratinized stratified squamous epithelial tissues is characteristic
Integument
Which of the following cadherin cytoplasmic domains links it to actin?
A catenin
Which of the following is not contained in the alpha lysosomal granules of platelets
Factors that disrupt parasite membranes
Which of the following is the largest leukocytes and have a kidney shaped nucleus?
Monocytes
Which of the following terms doesn’t refer to mature bone?
Woven
Correct lineage for a neutrophil
Myeloblast, promyelocyte, myelocyte, metamyelocyte, band cell, neutrophil
During the contraction of a sarcomere, shortening DOES NOT occur in which of the following?
A band only
In neuromuscular spindles intrafusal fibers within the neuromuscular spindles are supplied by which of the following fibers?
Gamma fibers
Which of the following types of collagen forms a mesh in basement membranes
type IV
The lamina cribrosa is associated with which of the following layers of the eye?
Sclera
Which of the following converts fibrinogen to fibrin
Thrombin
The epineurium contains Type ____ collagen and the endoneurium contains Type ____ collagen.
I; III
Which of the following types of cells myelinate axons in the CNS?
Oligodendrocytes
Which of the following types of cells are associated with the blood brain barrier?
Astrocytes
A stratified squamous, nonkeratinized epithelium with free nerve endings is characteristic of which of the following?
Corneal epithelium
Aqueous humor is first secreted into which of the following chambers of the eye?
Posterior chamber
Which of the following make up 60-70% of circulating leukocytes?
Neutrophils
Which of the following macromolecules is negatively charged polysaccharide consisting of repeated disaccharide units that maintains large, water-filled spaces in the ECM of connective tissue?
Glycosominoglycan
This protein extends from Z band of a sarcomere and serves as the template to regulate the length of an actin filament
Nebulin
Which of the following cell types have bilobed nucleus and specific granules containing major basic protein that disrupts parasite membranes?
Eosinophils
Which of the following statements BEST describes the epineurium?
It is a thin membrane surrounding a bundle of fascicles
The axons of which of the following cells form the optic nerve?
Ganglion cells
The cleaving of the non-helical terminal ends of pro-collagen, converting it into tropocollagen occurs where?
Immediately after secretion
Which of the following is NOT a characteristic of fibrocartilage?
Type II collagen
Which of the following is not part of a Haversian system?
Periosteum
Which of the following is the enzyme in osteoclasts that catalyzes the production of hydrogen ion?
Carbonic anhydrase II
In the myelinated sheath of peripheral axons, which of the following is important in binding together the outer leaflets of the Schwann cell plasmalemma and helping to compact the cytoplasm?
Major protein zero
T/F In cardiac muscle cells, gap junctions are associated with the transverse component of the intercalated disc
FALSE
In a skeletal muscle fiber, which of the following extends from one myofibril to another and to the sarcolemma?
Desmin
Which of the following ligands, derived from Weibel-Palade bodies, appears on the surface on the cell surface of endothelial cells when they are activated by inflammatory signaling?
P-selectin
Which of the following factors marks the end of both the intrinsic and extrinsic pathways?
Xa
Parathyroid hormones stimulate osteoblasts to secrete/express which of the following?
Only B and C
- M-CSF
- RANKL
Peripheral proteins form a cytoskeletal network in red blood cells and are bound to integral membrane proteins by which of the following?
Ankyrin
In a skeletal muscle fiber, which of the following functions to anchor actin to the sarcolemma?
Dystrophin
Which of the following is a peripheral protein that helps to maintain the biconcave shape of an erythrocyte?
Spectrin
